class Person {
    String name
}
 def properties = Collections.synchronizedMap([:])

        Person.metaClass.setJcrPath= { String value ->
            properties[System.identityHashCode(delegate) + "jcrPath"] = value
        }

        Person.metaClass.getJcrPath= {->
            properties[System.identityHashCode(delegate) + "jcrPath"]
        }

def p = new Person()

p.jcrPath ="lala"

assert(p.jcrPath =="lala")